Matty - You're probably aware of this already, but starting school clubs for something that can result in injury like MTB can have all kinds of legal red tape involved. The school itself may not want to accept the potential liability, so it may not allow the school name to be affiliated. And even if they do, there may be rules (depending on the school's BOE) about whether or not a non-employee of the school can be involved. That last one is a sad and cynical rule, but once again I think it's about liability. The info Zasker posted is probably full of the kind of things you'll have to deal with. I have a few family members who work in education and they'd be the first to tell you that sometimes great ideas are very difficult to implement because the schools just can't risk litigation.